1. Technical Field
The present invention relates to wireless communications and, more particularly, wireless communication system base stations and access points.
2. Related Art
Communication systems are known to support wireless and wire lined communications between wireless and/or wire lined communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards, including, but not limited to, IEEE 802.11, Bluetooth, Advanced Mobile Phone Services (AMPS), digital AMPS, Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Local Multipoint Distribution Systems (LMDS), Multipoint Multichannel Distribution Services (MMDS), and/or variations thereof.
Depending on the type of wireless communication system, a wireless communication device, such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, etc., communicates directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices tune their receivers and transmitters to the same channel or channels (e.g., one of a plurality of radio frequency (RF) carriers of the wireless communication system) and communicate over that channel(s). For indirect wireless communications, each wireless communication device communicates directly with an associated base station (e.g., for cellular services) and/or an associated access point (e.g., for an in-home or in-building wireless network) via an assigned channel. To complete a communication connection between the wireless communication devices, the associated base stations and/or associated access points communicate with each other directly, via a system controller, via the Public Switched Telephone Network (PSTN), via the Internet, and/or via some other wide area network.
Each wireless communication device includes a built-in radio transceiver (i.e., receiver and transmitter) or is coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.). As is known, the transmitter includes a data modulation stage, one or more intermediate frequency stages, and a power amplifier. The data modulation stage converts raw data into baseband signals in accordance with the particular wireless communication standard. The baseband signals are mixed with one or more local oscillations to produce RF signals either directly or through an intermediate frequency stage. The power amplifier amplifies the RF signals prior to transmission via an antenna.
As is also known, the receiver is coupled to the antenna and includes a low noise amplifier, one or more optional intermediate frequency stages, a filtering stage, and a data recovery stage. The low noise amplifier receives an inbound RF signal via the antenna and amplifies it. The one or more intermediate frequency stages (if present) mix the amplified RF signal with one or more local oscillations to convert the amplified RF signal into a baseband signal or an intermediate frequency (IF) signal. As used herein, the term “low IF” refers to both baseband and intermediate frequency signals. A filtering stage filters the low IF signals to attenuate unwanted out of band signals to produce a filtered signal. The data recovery stage recovers raw data from the filtered signal in accordance with the particular wireless communication standard.
To carry out filtering at the intermediate frequencies, Surface Acoustic Wave (SAW) filters are commonly used. The SAW filters have the drawback, however, of being bulky, heavy and expensive. An alternate approach to using a higher intermediate frequency that requires the SAW filters is to convert the RF signal to an intermediate frequency sufficiently low to allow the integration of on-chip channel selection filters. For example, some narrow band or low data rate systems, such as Bluetooth, use this low intermediate frequency design approach. This approach is advantageous in that the use of an intermediate conversion step is avoided.
In a wireless local area network, one common challenge is to maximize the effectiveness of the communication channels to each communication device wirelessly communicating with the access point. Generally, however, structural interference and multi-path interference within a building or dwelling reduce effectiveness of one or more communication links. Moreover, antennas are somewhat directional thereby resulting in signal quality being reduced or improved based upon antenna placement and orientation. Accordingly, it is common for a user to continuously move an access point or host device into different locations and/or orientations to find a placement for which each communication device, in its current location, may establish a communication link between the host and the access point. Generally, however, determining a satisfactory location and orientation of the host or access point is a hit or miss proposition. Moreover, while a location may be determined as satisfactory, the quality of the communication link may not be optimal thereby potentially reducing throughput rates and overall signal quality. What is needed, therefore, is a system and method for indicating, to a user of a base station, an access point or a WLAN host device, of an antenna orientation for a given position that substantially maximizes signal quality to each communication device communicatively coupled to the base station or access point.